Determining Pokemon's feelings towards you
When you use an item on one of your Pokemon outside of a battle, such as a Potion, the Pokemon will either move closer or away from you in the short intermission sequence. How far the Pokemon moves depends on how much it likes you. If it does not move at all, it feels neutral.

How To Get The Rainbow Pass
To get the rainbow pass (Island 4 - 7) you first need to defeat the elite four.Than you need to catch 60 pokemon and show prof oak he will update your pokedex to a national dex.Now go to 1 island and talk to celio he will say get the ruby and sapphire stones and bring them to me.Do this and show celio and he will reward you with a rainbow pass

Exp. Share Breakdown
This will describe 3 scenarios to help explain the signigicance of the Exp. Share item.

Part One - Normal Battle
This is when no pokemon on your team holds the Exp. Share. If three pokemon are used to defeat a foe, and the foe gives 60 EXP, the breakdown is as follows:
Pokemon1 - 20
Pokemon2 - 20
Pokemon3 - 20

Part 2 - Exp. Share doesn't hit the field
This is when a pokemon has the Exp. Share item, but does not participate in battle. In this scenario, PokemonE has the Exp. Share, and Pokemon1 and Pokemon2 were the only ones that participated in battle. The defeated pokemon will drop 60 EXP total.
PokemonE - 30
Pokemon1 - 15
Pokemon2 - 15

Mystery Gift
In any Pokemon Center, go to the clipboard by the shop owner and enter "Link Together With All." You will now have access to the mystery gift system.

Islands 1-3
To unlock islands 1-3 you must beat the first 7 gyms.

Unlock National Dex
Once you have beaten the Elite 4 and have more then 60 pokemon in the pokedex, go to Pallet Town and see the Professor. He gives you and Gary the National Dex, which allows you to view the entries of all 386 pokemon.

Trainer Card Stickers
Go to 'Island 4' and go to the bragget house where he asks you what you want to Brag about:

Level up fast in beginning of the game
At the beginning of the game you'll start out with one level 5 Pokemon. You can train it early and, have it at a decent level.

Once you start out with your first Pokemon. Battle Gary at first. (Or whatever you named your rival) Win that battle to level up to level 6. Now you can go into the wild. There walk around in the grass to encounter some enemies. Battle them. At this point of the game this is a great place to level up. Do this until you get "very little" number of EXP after a battle.

Long but Worthy Battle
If you find a Pokemon you want in the wild and you have some Timer Balls, just keep using Growl and all those no damage attacks. Then when the battle has gone on for about a minute, use one Timer Ball. If you didn't catch it, try it in another minute. The stat-weakening attacks will acctually help catch it!

SOME USEFUL TIPS
-Get The National Dex-
To get the National Dex, just beat the Elite Four with at least sixty pokemon in your Dex and after the credits. You'll arive in Pallet Town and Oak will upgrade u and Gary's Dex.

-Trade With Ruby-
To trade with Ruby/Sapphire, you need to fix the network machine on Island 1.

-Gettin The Legendaries-
Zapdos - Get in in the Power Plant like Red/Blue.
Articuno - Get in at Seafoam Island like Red/Blue.
Moltres - Can be found at Island One.
Mewtwo - Can be found in The Unknown Dungeon.

-Gettin The Legendary Dogs-
The Legendary Dogs appear wild anywhere after you beat the Elite Four depending on you starter. You can only find one pokemon in the game depending on the following starters u select:
Suicune : Charmander
Raikou : Squirtle
Entei : Bulbasaur

-Unlimited Time In The Safari Zone-
Go to the Safari Zone and walk into any area with grass and stop. Now touch the D-pad lightly but don't move anywhere. Now you'll see that your player just turned up/down. Now continue to do it in a rotation (ex Left, Down, Right, Up). Eventually u will encounter a pokemon while just rotating in te same spot.

How to get the Ruby and Sapphire plate & Deoxys and also Lugia and Ho-oH
You must fight the elite 4 with catching at least 60 pokemon, go and get the national dex to proffessor Oak then go to the moltres mountain again you will see the team rocket blocking the passage to a cave, beat them and go inside the cave, then in the deep part of it you can see the ruby plate, get it and take it to island 1's Pokemon Center take it to the scientist.
He'll give you a rainbow ticket to access island 4-7. Save Lorelei from being attack by team rocket in Icefall Cave on Four Island then find the Sapphire plate on Six Island and battle the team rocket in the Rocket Warehouse on Five Island.
You will fight again the elite four but different and hard pokemon to beat.
If you got the aurora ticket(like eon ticket to be given away) you can access island 8-9.

Get more ex.p share
If you have pokemon from ruby/saphire give any pokemon the ex.p share and trade onto your pokemon fire red/leaf green.

The Pokemart on Two Island
When you first visit Two Island, the local Pokemart will be severely limited in the items for sale. As you complete various tasks, more items will become available.

Special Recognition
Once you have collected all 200 Pokemon in this game, go to the Celadon Mansion and the man who is incharge of the Game Freak will give you a diploma.

Get into Saffron City!
OK,in FR&LG the guard won't let you pass.Go into Pokemon Mansion in Celadon city,& talk to the old lady.She'll give you some tea.Now go to the guard and he'll let u pass!!

National dex
Once you have beaten the Elite 4 and have more then 60 pokemon in the pokedex, go to Pallet Town and see the Professor. He gives you and Gary the National Dex, which allows you to view the entries of all 386 pokemon.

Easy Level Up
This is a way to level up your pokemon by 'abusing' in-game trainers and the battle rules. The relevant rules are as follows:

1. If you lose a battle, you pay prize money. If you don't have any money, you don't pay a prize.
2. If you lose against a Trainer, you go to the nearest Pokemon center, and you will have to fight the trainer again.

To abuse these rules, you'll need to set-up. There are 3 things you need to do to set up.

1. Blow all of your money (or as much as possible) on items. This will keep you from losing a large amount of money while leveling up.

2. Put all healing and reviving items in your PC. This will keep you from wasting items, and make it easier to level up. Trust me on this.

That's the set-up. To do it, fight a Trainer (the best trainer is probably Lorelei of the Elite Four). When fighting, beat all but their last pokemon. You will get expirience for the pokemon you beat, and the Exp. Share will level up lower level pokemon without entering battle. Now, let the last pokemon make your whole team faint. You will go back to the nearest pokemon center, but the pokemon who participated will have more expirience than before. Repeat as often as you like to get your team maxed out.